I like a high FOV in UT. I usually would run 90-100* there. Otherwise I tend to go for lower. I run Skyrim at 80-85 on my 16:9 monitor.

FOV sensitivity also depends on what monitor you're using though. I know there are some people still using 4:3 CRTs and games frequently look a hell of a lot different on those than a 16:9/10 screen for various reasons. Not all developers adjust FOV in the same way at different resolutions, etc. Some games are curiously designed in that you see considerably less on a big widescreen display than a 4:3/5:4 monitor.